Certain known cable transportation systems are described in documents CH Patent No. 671,929; AT Patent No. 404,010; U.S. Pat. No. 5,582,109; EP Patent No. 687,607; AT Patent No. 405,269; EP Patent No. 1,077,167; EP Patent No. 1,088,729; IT Patent No. 1,313,914; IT Patent No. 1,317,169; IT Patent No. 1,316,131; IT Patent No. 1,326,531; WO Patent Application No. 08/129,019; WO Patent Application No. 2009/019,259; and WO Patent Application No. 2009/053,485.
The tracks of cable transportation systems of these type sometimes have forks. One particular type is that in which the track forks into two at a stop station for two transportation units traveling in opposite directions. Generally speaking, cable transportation system tracks may comprise two-way single-rail portions, and two-rail portions along which the transportation units pass one another in opposite directions.
When the transportation units travel in opposite directions along the track, the system comprises two respective hauling cables operated in opposite directions. In certain know cable transportation systems, the hauling cables extend parallel to the track, between the rails, and are connected to the transportation units by clamps integral with the units. Therefore, in addition to ensuring continuity of the track, the switches must also be configured to avoid interfering with the hauling cable/s and clamps.
One example of a known switch for cable transportation systems is described in IT Patent No. 1,326,531, in which the switch comprises a track portion defined by two parallel curved rails extending along respective arcs, mounted on a pivot, and configured to connect different branches of the track, depending on the angular position of the pivot.
The above switch has proved successful, but has the drawback of comprising a moving part of considerable size and weight. Moreover, the pivot has to travel a long way to switch the rails, which therefore takes considerable time.